The subject matter of this application is directed to miniature electrical inductors and transformers and methods to manufacture these devices.
Transformers are used to transfer energy by inductive coupling between two sets of windings of the transformer. For example, a transformer may allow alternating voltages and/or currents of magnetically coupled windings to be stepped up or down. The ratio of the windings in a primary winding to those in a secondary winding determines the stepping ratio in ideal transformers.
Depending on the application, transformers are manufactured in varying sizes. Small transformers have been manufactured from discrete components. However, these transformers still take up significant amounts of space on the surface of a circuit board and are not always usable in high voltage applications. In addition, the manufacturing cost for transformers using discrete components can be significant.
Transformers have also been manufactured on dies of integrated circuits. However, manufacturing processes of such transformers includes depositing multiple layers of each material to form the transformer. Such manufacturing processes can be costly and take up significant amount of time. In addition, these transformers are not always usable in high voltage applications.
Accordingly, there is a need in the art for transformers that consume small amounts of space on the circuit board, are not expensive to manufacture, and can be included in high voltage applications.